list_devices

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the burden. It transparently describes the output fields and the practical consequence of ignoring the palette, but it does not disclose any operational behaviors such as whether the list is cached, ordered, or reflects live hardware state. For a zero-parameter read-only list, this is adequate but not rich.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact and front-loaded: a one-line purpose, a field list, and a single actionable sentence. No filler or redundancy; every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a no-param, no-output-schema tool, the description covers the key return fields (color_mode, colors, gamut, orientation, mono) and connects them to a concrete workflow. It loses a point because 'panel dims' is mentioned but the exact width/height field names are not explicitly listed, leaving minor ambiguity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so the schema already exhaustively covers them (100%). The description still adds value by explaining how the returned data should be used (match canvas w/h, avoid quantization), which earns the baseline 4.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource—'List registered display devices'—and immediately scopes the result to panel dimensions and color capabilities. It distinguishes itself from sibling list tools (list_widgets, list_pages) by naming display-device-specific fields.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It provides clear context for when to use: to obtain a target panel's width/height and design within its color palette so colors don't quantize. It does not explicitly name alternatives or exclusions, so not a 5, but the usage intent is well implied.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.